Polyacetylene fibril growth in soluble Ziegler-Natta catalysts
Free-standing polyacetylene films prepared by using the soluble Ziegler-Natta catalyst Ti(OBu)/sub 4//AlEt/sub 3/ are of great interest for they exhibit an electrical conductivity in the metallic regime, 10/sup 3/ (Omega cm)/sup -1/, when doped with various donors or acceptors. Scanning electron microscopy shows that the as-formed films consist of randomly oriented fibrils with a diameter and an interfibrillar distance depending upon the polymerization conditions. A detailed mechanistic study of the polymerization at -78/sup 0/C showed that the number of active centers for polymerization of acetylene, which consists of Ti/sup III/ species, is only one part per thousand of the total amount of catalyst. The morphology of the films and the fibril dimensions have a great effect on the properties of the polymer when it is doped with electron donors or acceptors, chemically or electrochemically. The doping process consists of the diffusion of the doping ion into the film and its fibrils with known diffusion rates under well-defined conditions. The homogeneity of the material is consequently affected by the diffusion factor, and therefore it is important to study the nature of the host polymer.
- Research Organization:
- Los Alamos National Lab., NM
- OSTI ID:
- 5321669
- Journal Information:
- Macromolecules; (United States), Journal Name: Macromolecules; (United States) Vol. 17; ISSN MAMOB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360404* -- Materials-- Polymers & Plastics-- Physical Properties-- (-1987)
ACETYLENE
ALKYNES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
FILMS
HYDROCARBONS
MORPHOLOGY
ORGANIC COMPOUNDS
POLYACETYLENES
POLYENES
POLYMERIZATION
THIN FILMS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIEGLER CATALYST